Pin message

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Annotations indicate a write operation (not read-only, not destructive). The description adds that it requires 'Pin Messages' permission and that channels have a 50-pin limit, which are useful behavioral details beyond annotations.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

Three concise sentences: purpose, permission, and limit. Every sentence adds unique value with no redundancy.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

For a simple pin tool, the description covers the essential context (purpose, permission, limit). Missing error behavior or result details, but overall adequate given no output schema.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema coverage is only 50% (channel and guild have descriptions, message_id and reason do not). The description does not add any parameter-specific meaning, leaving the agent uninformed about message_id format or reason usage.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

The description clearly states 'Pin a message in a channel.' and adds context about specific permissions and pin limits, which distinguishes it from siblings like unpin_message or edit_message.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

While the description implies when to use (needs permission and under pin limit), it does not explicitly state when not to use or compare with alternatives like unpin_message.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.